Actually, they were lined up for one-on-one critiques of their scores by Vänskä, the orchestra’s musical director. In town for the weeklong Minnesota Orchestra Composer Institute that culminates Friday night in a concert of their work, the emerging composers from across the United States and Sweden were about to hear their pieces played by a top symphony orchestra.

“I’m at an early stage in my career — I’m 27 — and musicians at this level of artistry have been practicing my work for two months,” Birman said.

In its 12th year, the Composer Institute is known as one of the premiere showcases of contemporary classical music. It’s part of the reason Minnesota has won the Leonard Bernstein Awards for Education Programming three times, more than any other orchestra. Several past attendees, including Anna Clyne and Ted Hearne, are considered rising stars on the new-music scene.

At a time when composers struggle to expand the musical appetite of audiences who expect Mozart and Beethoven, it’s a rare opportunity for developing talents to hear their pieces performed in a subscription concert, and to get feedback from both the maestro of a top symphony orchestra and its musicians.

“You’re giving me a huge challenge,” Vänskä told Kati Agócs of Boston during their discussion of her score. “The tempo is too fast. You can use my comments as you like, but never do that again, please.”

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Later in the hall, the orchestra rehearsed Agócs’ dense, bold, wide-ranging “Perpetual Summer,” by turns discordantly suspenseful and richly majestic, complete with crashing cymbals and even a siren.

“It’s great to have a major orchestra take a crack at it,” she said. “And Osmo made some excellent points about the tempo.”

It’s unusual for a musical director of Vänskä’s stature and overpacked schedule to devote so much time to nurturing newbies, and conduct such a concert himself.

He calls the program, “An investment in the future.

“You have to give them a chance like this,” he said. “If you cook food that no one eats, how can you ever know if it’s any good?”

The Institute, begun in 2001, was run by Pulitzer-winning composer Aaron Jay Kernis until he resigned in 2013 over frustration with the orchestra’s 16-month lockout.

Kevin Puts, whose “The Manchurian Candidate” will have its premiere with Minnesota Opera in April, was named to succeed Kernis.

“New music used to mean ‘weird,’ ” said Puts, a Pulitzer winner in 2012 for the Minnesota Opera commission “Silent Night.” “Now it’s more accessible, everyone’s trying to communicate with audiences.”

Friday’s concert requires a lot of dedication from musicians as well, said orchestra harpist Kathy Kienzle, who taught a workshop on how to write for the harp.

“It’s way more work than usual,” she said. “We never play concerts where we have to learn seven new pieces. Often I get annoyed with what they’ve done, but then I meet them and they’re so grateful, it’s worth it.”

The orchestra’s current season includes few new works. An Eric Whitacre program is coming in May. Composer Institute graduate Polina Nazaykinskaya’s “Winter Bells,” was performed last November.

On his way to rehearsal Thursday, Vänskä stressed the importance of composers being present when their work is practiced, so they can hear what’s “possible and impossible” for musicians to play.